In recent years, the radio-frequency performance test on a wireless terminal has attracted more and more attention. A whole machine receiving sensitivity performance test can objectively reflect the final emitting and receiving performance of a wireless terminal. At present, there are mainly two methods provided for evaluating the receiving sensitivity performance of a wireless terminal: one is known as passive test, which makes the determination based on the receiving sensitivity performance of the antenna and mainly focuses on evaluating the receiving sensitivity performance of a wireless terminal from the gain, the efficiency, the directional diagram and other radiation aspects of the antenna of the wireless terminal; and the other is known as active test, which tests spatial radio-frequency performances of a wireless terminal in a given microwave dark chamber, such as receiving sensitivity.
At present, only the wireless terminals passing full type approval (FTA) test can be sold on the market. In the FTA test, a radio-frequency performance test is mainly carried out on a wireless terminal in a cable connection mode, and no explicit regulation is given as to the spatial radio-frequency performance of the whole wireless terminal, however, over the air (OTA) test can make up the shortcomings of the FTA test in this aspect. Meanwhile, wireless terminal manufactures should have a clear understanding on the receiving sensitivity performance of the produced wireless terminals and need to improve the radio frequency emitting and receiving index of the wireless terminals through various measures; a wireless terminal with poor receiving sensitivity performance will bring much inconvenience to the user. In particular, when a wireless terminal is used for communication, the emitting and receiving performance thereof is reduced for the human body is close to the antenna of the wireless terminal, and consequently, the overall radio-frequency emitting and receiving performance of the wireless terminal is reduced. Therefore, the influence of the human body on the emitting and receiving performance of a wireless terminal should be quantitatively measured in the research and development process of the wireless terminal to carry out an optimization design so as to avoid a dramatic reduction in the emitting and receiving performance of the wireless terminal, that is, to reduce the electromagnetic coupling effect between the human body and an antenna. Transmitting parameters include total radiated power (TRP for short) and total radiated sensitivity (TRS for short).
TRS of a mobile terminal reflects the receiving sensitivity index of a wireless terminal on the whole radiating spherical surface as well as the fact that the receiving sensitivity of the whole wireless terminal is related to the conducting sensitivity of the wireless terminal and the receiving sensitivity of antenna.
                    TRS        =                              4            ⁢            π                                ∮                                          [                                                      1                                                                  EIS                        θ                                            ⁡                                              (                                                  Ω                          ;                          f                                                )                                                                              +                                      1                                                                  EIS                        φ                                            ⁡                                              (                                                  Ω                          ;                          f                                                )                                                                                            ]                            ⁢                              ⅆ                Ω                                                                        formula        ⁢                                  ⁢                  (          1          )                    
herein, effective isotropic sensitivity (EIS for short) defines an available antenna output power, for example, each polarization reaching the acceptable threshold, Ω is a three-dimensional angle for describing direction, f is frequency, θ and φ are angle parameters of an orthogonal polarization.
                    TRS        ≈                              2            ⁢            NM                                π            ⁢                                          ∑                                  n                  =                  0                                                  N                  -                  1                                            ⁢                                                          ⁢                                                ∑                                      m                    =                    0                                                        M                    -                    1                                                  ⁢                                                                  ⁢                                                      [                                                                  1                                                                              EIS                            θ                                                    ⁡                                                      (                                                                                          θ                                n                                                            ,                                                                                                φ                                  m                                                                ;                                f                                                                                      )                                                                                              +                                              1                                                                              EIS                            φ                                                    ⁡                                                      (                                                                                          θ                                n                                                            ,                                                                                                φ                                  m                                                                ;                                f                                                                                      )                                                                                                                ]                                    ⁢                                      sin                    ⁡                                          (                                              θ                        n                                            )                                                                                                                              (        2        )            
wherein N and M are multiple sampling intervals for θ and (φ; θn and φm, are testing angles;
EISθ(θn, φm) is the value of the horizontal polarization component of the equivalent omnidirectional receiving power of the testing point having angles of θn and φm, with the unit being milliwatt;
EISφ(θn, φm) is the value of the vertical polarization component of the equivalent omnidirectional receiving power of the testing point having angles of θn and φm, with the unit being milliwatt.
The currently used device and method for testing TRS of spatial radio-frequency performances both aim at a voice mode, only relating to free space or human head and not completely reflecting the influence of the electromagnetic coupling of antenna and human hand or even human body in a data mode, thus, the test result of the scheme above is not accurate.